Definition of pycnometer in English:

pycnometer

Pronunciation /pɪkˈnɒmɪtə/

noun

(also pyknometer)
  • A container used for finding the relative density of a liquid by measuring its weight when filled with the liquid and comparing it with the weight when filled with water.

    Ostwald pycnometer.

Origin

Mid 19th century; earliest use found in John Thudichum (1829–1901), physician and chemist. From pycno- + -meter.